Shiftless wafer blades

ABSTRACT

In an embodiment, a system includes: a cassette comprising a slit opening configured to house a wafer; a blade configured to move the wafer to and from the slit opening by extending into the slit opening, wherein a blade thickness of the blade is at most ⅖ of a height of the slit opening and wherein the blade is configured to secure the wafer within a pocket on the blade that is at least ⅔ of a wafer thickness of the wafer.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/908,153, filed Jun. 22, 2020, which is a continuation ofU.S. patent application Ser. No. 16/123,413, filed on Sep. 6, 2018, nowU.S. Pat. No. 10,699,931, which claims priority to China Application No.201710795387.8 filed Sep. 6, 2017, each of which is incorporated byreference herein in its entirety.

BACKGROUND

In the fabrication processes for a semiconductor device, numerousprocessing steps must be carried out on a semiconductor substrate beforethe device is fabricated. The numerous processes may be as many asseveral hundred processing steps. Each processing step is executed in aprocess chamber, such as an etcher, a physical vapor deposition chamber(a.k.a., a sputtering chamber), a chemical vapor deposition chamber, andthe like.

In the vast majority of the processing steps, a special environment ofeither a high vacuum, a low vacuum, a gas plasma or other chemicalenvironment may be provided for the wafer. For instance, in a sputteringchamber, a high vacuum environment may first be provided surrounding thewafer such that metal particles sputtered from a metal target can travelto and deposit on an exposed surface of the wafer. In other processchambers, such as in a plasma enhanced chemical vapor depositionchamber, a plasma cloud of a reactant gas or gases is formed over awafer positioned in a chamber such that deposition of a chemicalsubstance can occur on the wafer. During any processing step, the wafermust also be kept in an extremely clean environment without the dangerof being contaminated. The processing of a wafer therefore must beconducted in a hermetically sealed environment that is completelyisolated from the ambient atmosphere.

In a wafer processing system, the handling of wafers between the variouschambers must be carefully conducted to avoid damage to the wafers. Toaccomplish such purpose, the wafer is handled by a wafer transfersystem. The wafer transfer system may consist mainly of a robotichandler which handles all wafer transfers by a single, planar, two-axis,random access, cassette-to-cassette motion. A major component of therobotic handler is a wafer blade. The wafer blade may operate under ahigh-temperature transfer environment of up to 700° Celsius, forexample, without incurring contamination.

The positioning of a wafer on the wafer blade may result in two surfacesbeing positioned face-to-face. When the two surfaces are positioned faceto face, the wafer may slip off the wafer blade during transport and thecontact between the wafer blade and wafer may cause damage to the waferand/or the wafer blade. Also, when a wafer falls off the blade, thewafer may be either severely damaged or broken, resulting in a totalloss.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that various features are not necessarily drawn to scale. In fact,the dimensions and geometries of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1A is a plan view of a shiftless wafer blade, in accordance withsome embodiments.

FIG. 1B is a view of certain outside corners of the shiftless waferblade toward a rear portion of the shiftless wafer blade, in accordancewith some embodiments.

FIG. 1C is a plan view of the shiftless wafer blade with a wafer on top,in accordance with some embodiments.

FIG. 1D is a view of one of the forward protrusions with roundedcorners, in accordance with some embodiments.

FIG. 2A is a diagram of a wafer transfer system, in accordance with someembodiments.

FIG. 2B is a perspective diagram of the transfer chamber of wafertransfer system, in accordance with some embodiments.

FIG. 2C is a perspective diagram of the transfer chamber with the waferon top, in accordance with some embodiments.

FIG. 2D is a block diagram of various functional modules of the wafertransfer system, in accordance with some embodiments.

FIG. 3A is a cross sectional view of the wafer transfer systeminterfacing with a cassette, in accordance with some embodiments.

FIG. 3B is a cross section view of the shiftless wafer blade extendedinto a slit opening, in accordance with some embodiments.

FIG. 3C is a view of various slit openings of the cassette, inaccordance with some embodiments.

FIG. 4A is a cross sectional diagram of the shiftless wafer blade with awafer on top, in accordance with some embodiments.

FIG. 4B is a cross sectional diagram of the shiftless wafer blade with awafer flush with a top surface of the shiftless wafer blade, inaccordance with some embodiments.

FIG. 4C is a cross sectional diagram of a shiftless wafer blade with awafer not flush with a top surface of the wafer blade, in accordancewith some embodiments.

FIG. 5A is a diagram of a shiftless wafer blade that is simplyconnected, in accordance with some embodiments.

FIG. 5B is a diagram of a shiftless wafer blade with two openings, inaccordance with various embodiments.

FIG. 5C is a diagram of a shiftless wafer blade with three openings, inaccordance with various embodiments.

FIG. 5D is a diagram of a shiftless wafer blade with a single opening,in accordance with various embodiments.

FIG. 5E is a diagram of a shiftless wafer blade with a singlerectangular opening, in accordance with various embodiments.

FIG. 5F is a diagram of a shiftless wafer blade with four rectangularopenings, in accordance with various embodiments.

FIG. 5G is a diagram of a shiftless wafer blade with a single roundedforward protrusion, in accordance with various embodiments.

FIG. 5H is a diagram of a shiftless wafer blade with three forwardprotrusions, in accordance with various embodiments.

FIG. 6 is a flow chart of a shiftless wafer blade transfer process, inaccordance with some embodiments.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following disclosure describes various exemplary embodiments forimplementing different features of the subject matter. Specific examplesof components and arrangements are described below to simplify thepresent disclosure. These are, of course, merely examples and are notintended to be limiting. For example, it will be understood that when anelement is referred to as being “connected to” or “coupled to” anotherelement, it may be directly connected to or coupled to the otherelement, or one or more intervening elements may be present.

In addition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

The present disclosure provides various embodiments of a shiftless waferblade. A shiftless wafer blade may include a deep wafer pocket, a thinprofile, and dulled corners. The deep wafer pocket may have a depth thatis at least ⅔ of a thickness of a wafer configured to sit on theshiftless wafer blade (e.g., within the deep wafer pocket of theshiftless wafer blade). Having a deep wafer pocket allows a wafer to bemore secure within the deep wafer pocket than with a pocket that is lessthan ⅔ of a thickness of the wafer. Also, a wafer may be housed within aslit opening of a cassette for transport with other wafers in thecassette. The shiftless wafer blade may have a thin profile that is atmost (e.g., at or less than) ⅖ of a height of the slit opening.

Lastly, the shiftless wafer blade may secure a wafer using contours orformations along the surface of the shiftless wafer blade. For example,the contours may form an outline for the deep wafer pocket. The cornersof the shiftless wafer blade may be rounded, or greater than 90 degreesbetween intersecting surfaces to prevent damage to the corners of theshiftless wafer blade and damage to other objects (e.g., the wafer) fromcontact with the shiftless wafer blade. In certain embodiments, theshiftless wafer blade may be configured to extend into a slit opening toan extension depth and have all outside corners of the wafer blade tothe extension depth be greater than 90 degrees between intersectingsurfaces (e.g., as rounded corners). In further embodiments, theshiftless wafer blade may have all exposed outside corners (e.g.,outside corners that can be contacted at a surface not covered by arobotic handler) be greater than 90 degrees between intersectingsurfaces (e.g., as rounded corners). The angles may be measured fromwithin the shiftless wafer blade. The outside corner may also describe atapered sidewall. The term “intersecting surfaces” may refer to asurface of a generally uniform gradient or slope, and the term “corner”may refer to a transition between the surfaces.

FIG. 1A is a plan view of a shiftless wafer blade 102, in accordancewith some embodiments. The shiftless wafer blade 102 may have variouscontours which provide structures on which a wafer may rest while beingsecured and transported by the shiftless wafer blade 102. These contoursmay include a lower pocket contour 104A and an upper pocket contour104B. As will be illustrated and discussed further below, a wafer mayrest within a deep wafer pocket between the upper pocket contour 104Band the lower pocket contour 104A. Visualized another way, the upperpocket contour 104B and lower pocket contour 104A may form an outlinefor two concentric circles where the area between the two concentriccircles forms the deep wafer pocket on which a wafer may rest. Also,each of the outside corners on the shiftless wafer blade, includingthose formed by the upper pocket contour 104B and the lower pocketcontour 104A, may be rounded, or greater than 90 degrees betweenintersecting surfaces. These outside corners include corners formed ofthe contour in both a horizontal and a vertical axis, where the verticalaxis is orthogonal to the horizontal axis. As noted above, an insidecorner may be a corner formed by two intersecting surfaces at an anglemeasured from the outside (e.g., external to the shiftless wafer blade)of greater than 180 degrees. These dimensions will be discussed infurther detail below.

The shiftless wafer blade 102 may also include forward protrusions 110.These forward protrusions 110 may be separated by a forward opening 112.The forward opening 112 may separate the forward protrusions 110 inorder to reduce an amount of material that makes up the shiftless waferblade 102, thus making the shiftless wafer blade 102 lighter and withless bulk. The forward opening 112 and forward protrusions 110 may bedescribed as being forward due to their being away from a rear portionof the shiftless wafer blade that may be covered by a robotic handler.The robotic handler will be discussed in further detail below. Inaddition to the forward opening 112, the shiftless wafer blade 102 mayinclude two circular openings 114, two elongated openings 116, and arear opening 118. Furthermore, the shiftless wafer blade may have anelongated outline that extends further along one axis than another.

FIG. 1B is a view of certain outside corners of the shiftless waferblade 102 toward a rear portion of the shiftless wafer blade 102, inaccordance with some embodiments. The outside corners may be part of thelower pocket contour 104A and the upper pocket contour 104B. Morespecifically, the both the lower pocket contour 104A and the upperpocket contour 104B may include a vertical outside corner 120A and ahorizontal outside corner 120B. The vertical outside corner may be acorner formed by two intersecting surfaces, that intersect more along ahorizontal axis than a vertical axis, at an angle measured from withinthe shiftless wafer blade of greater than 90 degrees. The horizontaloutside corner may be a corner fainted by two intersecting surfaces,that intersect more along a vertical axis than a horizontal axis, at anangle measured from within the shiftless wafer blade of greater than 90degrees. The horizontal axis may be an axis along which a height of theshiftless wafer blade extends.

FIG. 1C is a plan view of the shiftless wafer blade 102 with a wafer 130on top, in accordance with some embodiments. As noted above, the wafer130 may rest on the shiftless wafer blade 120 in the deep wafer pocketbetween the lower pocket contour and the upper pocket contour. Also,portions of the forward protrusions 110 may be exposed from under thewafer 130 and a rear part 132 of the shiftless wafer blade may also beexposed but may be substantially covered by the robotic handler, as willbe illustrated below.

FIG. 1D is a view of one of the forward protrusions 110 with roundedcorners, in accordance with some embodiments. As illustrated anddiscussed above, each of the corners of the forward protrusions may berounded, or greater than 90 degrees between intersecting surfaces.

FIG. 2A is a diagram of a wafer transfer system 202, in accordance withsome embodiments. The wafer transfer system 202 may include two cassetteload locks 204, three process chambers 206, three cooling chambers 208and a transfer chamber 210. The transfer chamber 210 may be isolatedfrom the cassette load locks 204, the process chambers 206 and thecooling by slit valves. The transfer chamber 210 may include a robotichandler 212 that includes the above referenced shiftless wafer blade.

Each of the process chambers 206 may be capable of processing a singlewafer for achieving wafer-to-wafer repeatability and control. An exampleof the process chambers 206 may be a rapid thermal processing chamber.The temperatures in the process chambers may be further closed-loopcontrolled for accuracy.

The handling of wafers between the cassette load locks 204, processchambers 206, cooling chambers 208 and the transfer chamber 210 may becarefully conducted to avoid damage to the wafers. To accomplish suchpurpose, the wafer is handled by a robotic handler 212. The robotichandler 212 may handle all wafer transfers by a single, planar,two-axis, random access, cassette-to-cassette motion. A major componentof the robotic handler 212 is a shiftless wafer blade. In certainembodiments, the shiftless wafer blade may be composed of high-purityquartz to permit high-temperature transfer at up to, for example, about700° centigrade without incurring contamination. In other embodiments,the shiftless wafer blade may be composed of at least one of: a ceramic(e.g., quartz), a metal (e.g., stainless steel), an aluminum alloy, oraluminum oxide.

FIG. 2B is a perspective diagram of the transfer chamber 210 of wafertransfer system, in accordance with some embodiments. The transferchamber 210 may include the robotic handler 212 with the shiftless waferblade 102 attached. The shiftless wafer blade 102 may be attached byhaving the rear part 132 of the shiftless wafer blade 102 connected toand sandwiched by the robotic handler 212. The connection of theshiftless wafer blade 102 with the robotic handler may be performed in aconventional manner and will not be discussed in detail herein.

FIG. 2C is a perspective diagram of the transfer chamber 210 with thewafer 130 on top, in accordance with some embodiments. The combinationof the robotic handler 212 and the wafer 130 may generally cover theshiftless wafer blade 102. However, portions of the forward protrusions110 may be exposed from under the wafer 130.

FIG. 2D is a block diagram of various functional modules of the wafertransfer system 202, in accordance with some embodiments. Thesefunctional modules may be present in addition to the various features ofthe wafer transfer system discussed above. The wafer transfer system 202may include a processor 254. In further embodiments, the processor 254may be implemented as one or more processors.

The processor 254 may be operatively connected to a computer readablestorage 256 (e.g., a memory and/or data store), a network connection258, a user interface 260, and a controller 262. In some embodiments,the computer readable storage 256 may include process logic that mayconfigure the processor 254 to perform the various processes discussedherein. The computer readable storage may also store data, such asoperational instructions for a shiftless wafer blade transfer process,identifiers for a wafer, identifiers for a shiftless wafer blade,identifiers for a cassette, and any other parameter or information thatmay be utilized to perform the various processes discussed herein.

The network connection 258 may facilitate a network connection of thewafer transfer system 202 with various devices and/or components of thewafer transfer system 202 that may communicate within or external to thewafer transfer system 202. In certain embodiments, the networkconnection 258 may facilitate a physical connection, such as a line or abus. In other embodiments, the network connection 258 may facilitate awireless connection, such as over a wireless local area network (WLAN)by using a transmitter, receiver, and/or transceiver. For example, thenetwork connection 258 may facilitate a wireless or wired connectionwith the processor 254 and the controller 262. Also, the networkconnection 258 may enable communication between a valve and a shutteractuator, or between a wafer support and rotational ring, as moderatedby the processor 254.

The wafer transfer system 202 may also include a user interface 260. Theuser interface may include any type of interface for input and/or outputto an operator of the wafer transfer system 202, including, but notlimited to, a monitor, a laptop computer, a tablet, or a mobile device,etc.

The wafer transfer system 202 may include a controller 262. Thecontroller 262 may be configured to control various physical apparatusesthat control movement or functionality of the wafer transfer system 202,such as for a robotic handler, a door, a cassette and the like. Forexample, the controller 262 may control a motor that may move a robotichandler, a door, or a cassette. The controller may be controlled by theprocessor and may carry out the various aspects of the various processesdiscussed herein.

FIG. 3A is a cross sectional view of the wafer transfer system 202interfacing with a cassette 230, in accordance with some embodiments.The cassette 230 may be part of the above referenced cassette loadlocks. The cassette 230 may include multiple slit openings 310 that areeach configured to house a wafer. The wafers may be of generally uniformsize and shape. Therefore, the slit openings may also each be ofgenerally uniform size and shape.

The robotic handler 212 may be coupled with the shiftless wafer blade102. The shiftless wafer blade 102 may be attached by having the rearpart 132 of the shiftless wafer blade 102 connected to and sandwiched bythe robotic handler 212. Accordingly, part of the rear part 132 of theshiftless wafer blade may be within the robotic handler 212 and notexposed to an area external to the robotic handler 212. In certainembodiments, the shiftless wafer blade may have all exposed outsidecorners (e.g., outside corners that can be contacted at a surface notcovered by a robotic handler) be greater than 90 degrees betweenintersecting surfaces.

In certain embodiments, the shiftless wafer blade 102 may be configuredto extend into the slit opening 310 to an extension depth 312 and haveall outside corners of the wafer blade to the extension depth be greaterthan 90 degrees between intersecting surfaces.

FIG. 3B is a cross sectional diagram of the shiftless wafer blade 102extended into the slit opening 310, in accordance with some embodiments.When extended into the cassette, the shiftless wafer blade 102 may havea certain amount of clearance both above and below the shiftless waferblade 102. In certain embodiments, the wafer (not illustrated in FIG.3B) may be moved in the slit opening 310 from a lower position to anupper position via pins (not illustrated) to extend above the shiftlesswafer blade 102 and then be lowered onto the shiftless wafer blade 102within the deep wafer pocket. The movement of the wafer within the slitopening 310 onto the shiftless wafer blade 102 may be performed in aconventional manner and will not be discussed in further detail herein.As noted above, the shiftless wafer blade may have a thin profile 320that is at most (e.g., at or less than) ⅖ of a height 322 of the slitopening 310, in accordance with some embodiments.

FIG. 3C is a view of various slit openings of the cassette, inaccordance with some embodiments. The forward protrusions 110 of thewafer blade are illustrated within a particular slit opening 310. Also,as illustrated, the cassette may have multiple slit openings 310arranged in a vertical manner, with one above or below another.

FIG. 4A is a cross sectional diagram of the shiftless wafer blade 102with a wafer 402 on top, in accordance with some embodiments. Theshiftless wafer blade 102 may include the deep wafer pocket 403 whichhas a depth (e.g., height) that is at least ⅔ of a thickness of thewafer 402. The deep wafer pocket 403 may be part of the contours whichdefine a region in which the wafer 402 may be secured. These contoursmay include the lower pocket contour 104A and the upper pocket contour104B. The wafer 402 may rest within the deep wafer pocket between theupper pocket contour 104B and the lower pocket contour 104A. Visualizedanother way, the upper pocket contour 104B and lower pocket contour 104Amay form an outline for two concentric circles where the area betweenthe two concentric circles forms a surface on which a wafer may rest.Also, each of the outside corners as formed by the upper pocket contour104B and the lower pocket contour 104A may be rounded, or greater than90 degrees between intersecting surfaces. These outside corners includecorners formed of the contour in both a horizontal and a vertical axis,where the vertical axis is orthogonal to the horizontal axis.

Also, as noted above, the shiftless wafer blade 102 may have a thinprofile with a thickness 410 that is at most (e.g., at or less than) ⅖of a height of the slit opening of a cassette. By being at most (e.g.,at or less than) ⅖ of a height of the slit opening of a cassette, theshiftless wafer blade 102 may have sufficient clearance to avoidundesirably contacting the cassette due to perturbations (e.g.,vibrations or other forces) of a robotic handler in motion. Thethickness 410 of the shiftless wafer blade may also be described as aheight from the upper pocket contour 104B to the bottom 412 of theshiftless wafer blade 102. The shiftless wafer blade 102 may also have asecond thickness 414 that is from the lower pocket contour 104A to thebottom 412 of the shiftless wafer blade 102. Furthermore, the shiftlesswafer blade 102 may have a third thickness 418 from a lowest surface 416to the bottom 412 of the shiftless wafer blade 102. In variousembodiments, the opening between the lower pocket contour 104A to thelowest surface 416 of the shiftless wafer blade 102 may be referred toas a lower opening 420. The lower opening 420 may be an open space toprevent the wafer's 402 adherence to the shiftless wafer blade 102 byvacuum forces via providing an air pocket or open space between theshiftless wafer blade 102 and the wafer 402. The lower opening 420 maybe laterally surrounded by the deep wafer pocket 403.

FIG. 4B is a cross sectional diagram of the shiftless wafer blade 102with a wafer 430 flush with a top surface 432 of the shiftless waferblade 102, in accordance with some embodiments. The wafer 430 may sitwithin the deep wafer pocket 403, which shares a same height (e.g.,thickness) as the wafer 430. Accordingly, the deep wafer pocket 403 mayhave a depth that is at least ⅔ of a thickness of the wafer 402. Byhaving a depth that is at least ⅔ of the thickness of the wafer 402, thewafer 430 may be secure from shifting out of the shiftless wafer blade102 due to perturbations (e.g., vibrations or other forces) of a robotichandler in motion. Beneath the wafer 430, the lower opening 420 may bean open space to prevent the wafer's 430 adherence to the shiftlesswafer blade 102 by vacuum forces, as discussed above.

FIG. 4C is a cross sectional diagram of a shiftless wafer blade 102 witha wafer not flush with a top surface of the wafer blade, in accordancewith some embodiments. The wafer 440 may sit within the deep waferpocket 403, which is not of a same height as the wafer 430. Accordingly,the deep wafer pocket 403 may be at least ⅔ of a thickness of the wafer440. Beneath the wafer 440, the lower opening 420 may be an open spaceto prevent the wafer's 440 adherence to the shiftless wafer blade 102 byvacuum forces, as discussed above.

FIG. 5A is a diagram of a shiftless wafer blade 502 that is simplyconnected, in accordance with some embodiments. Being simply connecteddescribes a topological space without holes such that any loop formedalong the topological space can be contracted to a point. The shiftlesswafer blade 502 may have no openings but have two rounded forwardprotrusions 504. A reference outline for a wafer is illustrated indotted lines 506, from which a contour on the shiftless wafer blade 502along the reference dotted lines 506 may be configured to secure a waferon the shiftless wafer blade 502 in a deep wafer pocket during wafertransport.

As noted above, the deep wafer pocket of the shiftless wafer blade 502may have a depth that is at least ⅔ of a thickness of a wafer configuredto sit within the deep wafer pocket. Also, the shiftless wafer blade 502may have all outside corners of the shiftless wafer blade 502 to anextension depth 508 be greater than 90 degrees between intersectingsurfaces. The angles may be measured from within the shiftless waferblade 502. The intersecting surfaces may refer to a surface of agenerally uniform gradient or slope, and the corner may refer to atransition between the surfaces. The extension depth 508 may refer to adepth within a slit opening in which the shiftless wafer blade 502 mayextend to retrieve a wafer. The slit opening may be an opening withinthe cassette in which the wafer that sits within the deep pocket of theshiftless wafer blade 502 may rest. In other embodiments, the shiftlesswafer blade 502 may have all exposed outside corners not covered by therobotic handler be greater than 90 degrees between intersectingsurfaces. The rear portion 509 of the shiftless wafer blade 502 may becovered by a robotic handler. Lastly, the shiftless wafer blade 502 mayhave a thin profile that is at most (e.g., at or less than) ⅖ of aheight of a slit opening.

FIG. 5B is a diagram of a shiftless wafer blade 510 with two openings,512 in accordance with various embodiments. The two openings 512 mayhave a rounded portion 514 that extends into part of a forwardprotrusion 515 of the shiftless wafer blade 510. A reference outline fora wafer is illustrated in dotted lines 516, from which a contour on theshiftless wafer blade 510 along the reference dotted lines 518 may beconfigured to secure a wafer on the shiftless wafer blade 510 in a deepwafer pocket during wafer transport.

As noted above, the deep wafer pocket of the shiftless wafer blade 510may have a depth that is at least ⅔ of a thickness of a wafer configuredto sit within the deep wafer pocket. Also, the shiftless wafer blade 510may have all outside corners of the shiftless wafer blade 510 to anextension depth 518 be greater than 90 degrees between intersectingsurfaces. The angles may be measured from within the shiftless waferblade 510. The intersecting surfaces may refer to a surface of agenerally uniform gradient or slope, and the corner may refer to atransition between the surfaces. The extension depth 518 may refer to adepth within a slit opening in which the shiftless wafer blade 510 mayextend to retrieve a wafer. The slit opening may be an opening withinthe cassette in which the wafer that sits within the deep pocket of theshiftless wafer blade 510 may rest. In other embodiments, the shiftlesswafer blade 510 may have all exposed outside corners not covered by therobotic handler be greater than 90 degrees between intersectingsurfaces. The rear portion 519 of the shiftless wafer blade 510 may becovered by a robotic handler. Lastly, the shiftless wafer blade 510 mayhave a thin profile that is at most (e.g., at or less than) ⅖ of aheight of a slit opening.

FIG. 5C is a diagram of a shiftless wafer blade 520 with three openings522A, 522B, in accordance with various embodiments. Two openings 522A ofthe three openings 522A, 522B may have a rounded portion 524 thatextends into part of a forward protrusion 525 of the shiftless waferblade. One opening 522B of the three openings may be of a rectangularshape between the two openings 522A. A reference outline for a wafer isillustrated in dotted lines 526, from which a contour on the shiftlesswafer blade 520 along the reference dotted lines 528 may be configuredto secure a wafer on the shiftless wafer blade 520 in a deep waferpocket during wafer transport.

As noted above, the deep wafer pocket of the shiftless wafer blade 520may have a depth that is at least ⅔ of a thickness of a wafer configuredto sit within the deep wafer pocket. Also, the shiftless wafer blade 520may have all outside corners of the shiftless wafer blade 520 to anextension depth be greater than 90 degrees between intersectingsurfaces. The angles may be measured from within the shiftless waferblade 520. The intersecting surfaces may refer to a surface of agenerally uniform gradient or slope, and the corner may refer to atransition between the surfaces. The extension depth 528 may refer to adepth within a slit opening in which the shiftless wafer blade 520 mayextend to retrieve a wafer. The slit opening may be an opening withinthe cassette in which the wafer that sits within the deep pocket of theshiftless wafer blade 520 may rest. In other embodiments, the shiftlesswafer blade 520 may have all exposed outside corners not covered by therobotic handler be greater than 90 degrees between intersectingsurfaces. The rear portion 529 of the shiftless wafer blade 520 may becovered by a robotic handler. Lastly, the shiftless wafer blade 520 mayhave a thin profile that is at most (e.g., at or less than) ⅖ of aheight of a slit opening.

FIG. 5D is a diagram of a shiftless wafer blade 530 with a singleopening 532, in accordance with various embodiments. The single opening532 may have rounded portions 534 that extends into part of a forwardprotrusion 535 of the shiftless wafer blade 530. A reference outline fora wafer is illustrated in dotted lines 536, from which a contour on theshiftless wafer blade 530 along the reference dotted lines 538 may beconfigured to secure a wafer on the shiftless wafer blade 530 in a deepwafer pocket during wafer transport.

As noted above, the deep wafer pocket of the shiftless wafer blade 530may have a depth that is at least ⅔ of a thickness of a wafer configuredto sit within the deep wafer pocket. Also, the shiftless wafer blade 530may have all outside corners of the shiftless wafer blade 530 to anextension depth be greater than 90 degrees between intersectingsurfaces. The angles may be measured from within the shiftless waferblade 530. The intersecting surfaces may refer to a surface of agenerally uniform gradient or slope, and the corner may refer to atransition between the surfaces. The extension depth 538 may refer to adepth within a slit opening in which the shiftless wafer blade 530 mayextend to retrieve a wafer. The slit opening may be an opening withinthe cassette in which the wafer that sits within the deep pocket of theshiftless wafer blade 530 may rest. In other embodiments, the shiftlesswafer blade 530 may have all exposed outside corners not covered by therobotic handler be greater than 90 degrees between intersectingsurfaces. The rear portion 539 of the shiftless wafer blade 530 may becovered by a robotic handler. Lastly, the shiftless wafer blade 530 mayhave a thin profile that is at most (e.g., at or less than) ⅖ of aheight of a slit opening.

FIG. 5E is a diagram of a shiftless wafer blade 540 with a singlerectangular opening 542, in accordance with various embodiments. Areference outline for a wafer is illustrated in dotted lines 546, fromwhich a contour on the shiftless wafer blade 540 along the referencedotted lines 546 may be configured to secure a wafer on the shiftlesswafer blade 540 in a deep wafer pocket during wafer transport.

As noted above, the deep wafer pocket of the shiftless wafer blade 540may have a depth that is at least ⅔ of a thickness of a wafer configuredto sit within the deep wafer pocket. Also, the shiftless wafer blade 540may have all outside corners of the shiftless wafer blade 540 to anextension depth be greater than 90 degrees between intersectingsurfaces. The angles may be measured from within the shiftless waferblade 540. The intersecting surfaces may refer to a surface of agenerally uniform gradient or slope, and the corner may refer to atransition between the surfaces. The extension depth 548 may refer to adepth within a slit opening in which the shiftless wafer blade 540 mayextend to retrieve a wafer. The slit opening may be an opening withinthe cassette in which the wafer that sits within the deep pocket of theshiftless wafer blade 540 may rest. In other embodiments, the shiftlesswafer blade 540 may have all exposed outside corners not covered by therobotic handler be greater than 90 degrees between intersectingsurfaces. The rear portion 549 of the shiftless wafer blade 540 may becovered by a robotic handler. Lastly, the shiftless wafer blade 540 mayhave a thin profile that is at most (e.g., at or less than) ⅖ of aheight of a slit opening.

FIG. 5F is a diagram of a shiftless wafer blade 550 with fourrectangular openings 552A, 552B, in accordance with various embodiments.Two outer openings 552A of the four rectangular openings 552A, 552B maybe longer than two inner openings 552B but not extend into a forwardprotrusion 555 of the shiftless wafer blade. The two inner openings 552Bmay have a same width but not a same length as the two outer openings552A and be between the two outer openings 552A. A reference outline fora wafer is illustrated in dotted lines 556, from which a contour on theshiftless wafer blade 550 along the reference dotted lines 556 may beconfigured to secure a wafer on the shiftless wafer blade 550 in a deepwafer pocket during wafer transport.

As noted above, the deep wafer pocket of the shiftless wafer blade 550may have a depth that is at least ⅔ of a thickness of a wafer configuredto sit within the deep wafer pocket. Also, the shiftless wafer blade 550may have all outside corners of the shiftless wafer blade 550 to anextension depth be greater than 90 degrees between intersectingsurfaces. The angles may be measured from within the shiftless waferblade 550. The intersecting surfaces may refer to a surface of agenerally uniform gradient or slope, and the corner may refer to atransition between the surfaces. The extension depth 558 may refer to adepth within a slit opening in which the shiftless wafer blade 550 mayextend to retrieve a wafer. The slit opening may be an opening withinthe cassette in which the wafer that sits within the deep pocket of theshiftless wafer blade 550 may rest. In other embodiments, the shiftlesswafer blade 550 may have all exposed outside corners not covered by therobotic handler be greater than 90 degrees between intersectingsurfaces. The rear portion 559 of the shiftless wafer blade 550 may becovered by a robotic handler. Lastly, the shiftless wafer blade 550 mayhave a thin profile that is at most (e.g., at or less than) ⅖ of aheight of a slit opening.

FIG. 5G is a diagram of a shiftless wafer blade 560 with a singlerounded forward protrusion 564, in accordance with various embodiments.The shiftless wafer blade 560 may also be simply connected withoutopenings. The shiftless wafer blade 502 may have the single roundedprotrusion 564. A reference outline for a wafer is illustrated in dottedlines 566, from which a contour on the shiftless wafer blade 560 alongthe reference dotted lines 566 may be configured to secure a wafer onthe shiftless wafer blade 560 in a deep wafer pocket during wafertransport.

As noted above, the deep wafer pocket of the shiftless wafer blade 560may have a depth that is at least ⅔ of a thickness of a wafer configuredto sit within the deep wafer pocket. Also, the shiftless wafer blade 560may have all outside corners of the shiftless wafer blade 560 to anextension depth be greater than 90 degrees between intersectingsurfaces. The angles may be measured from within the shiftless waferblade 560. The intersecting surfaces may refer to a surface of agenerally uniform gradient or slope, and the corner may refer to atransition between the surfaces. The extension depth 568 may refer to adepth within a slit opening in which the shiftless wafer blade 560 mayextend to retrieve a wafer. The slit opening may be an opening withinthe cassette in which the wafer that sits within the deep pocket of theshiftless wafer blade 560 may rest. In other embodiments, the shiftlesswafer blade 560 may have all exposed outside corners not covered by therobotic handler be greater than 90 degrees between intersectingsurfaces. The rear portion 569 of the shiftless wafer blade 560 may becovered by a robotic handler. Lastly, the shiftless wafer blade 560 mayhave a thin profile that is at most (e.g., at or less than) ⅖ of aheight of a slit opening.

FIG. 5H is a diagram of a shiftless wafer blade 570 with three forwardprotrusions 575A, 575B, in accordance with various embodiments. A singlecentral forward protrusion 575A may extend longer than and be flanked bytwo outer forward protrusions 575B. The shiftless wafer blade 570 mayalso be simply connected without openings. A reference outline for awafer is illustrated in dotted lines 576, from which a contour on theshiftless wafer blade 570 along the reference dotted lines 576 may beconfigured to secure a wafer on the shiftless wafer blade 570 in a deepwafer pocket during wafer transport.

As noted above, the deep wafer pocket of the shiftless wafer blade 570may have a depth that is at least ⅔ of a thickness of a wafer configuredto sit within the deep wafer pocket. Also, the shiftless wafer blade 570may have all outside corners of the shiftless wafer blade 570 to anextension depth be greater than 90 degrees between intersectingsurfaces. The angles may be measured from within the shiftless waferblade 570. The intersecting surfaces may refer to a surface of agenerally uniform gradient or slope, and the corner may refer to atransition between the surfaces. The extension depth 578 may refer to adepth within a slit opening in which the shiftless wafer blade 570 mayextend to retrieve a wafer. The slit opening may be an opening withinthe cassette in which the wafer that sits within the deep pocket of theshiftless wafer blade 570 may rest. In other embodiments, the shiftlesswafer blade 570 may have all exposed outside corners not covered by therobotic handler be greater than 90 degrees between intersectingsurfaces. The rear portion 579 of the shiftless wafer blade 570 may becovered by a robotic handler. Lastly, the shiftless wafer blade 570 mayhave a thin profile that is at most (e.g., at or less than) ⅖ of aheight of a slit opening.

FIG. 6 is a flow chart of a shiftless wafer blade transfer process 600,in accordance with some embodiments. The wafer blade transfer process600, may be performed by a wafer transfer system, as introduced above.It is noted that the process 600 is merely an example, and is notintended to limit the present disclosure. Accordingly, it is understoodthat additional operations may be provided before, during, and after theprocess 600 of FIG. 6 , certain operations may be omitted, certainoperations may be performed concurrently with other operations, and thatsome other operations may only be briefly described herein.

At operation 602, a shiftless wafer blade may receive a wafer. The wafermay be received, for example, within a slit opening of a cassette and/ora chamber. As noted above, the chambers may be, for example, a processchambers or a cooling chamber. Examples of processing chambers mayinclude an etching chamber, a physical vapor deposition chamber), asputtering chamber, a chemical vapor deposition chamber, and the like.Also, in order to receive the wafer, the shiftless wafer blade may beextended into the cassette and/or extended into the chamber. Whenextended into the cassette the shiftless wafer blade may have a certainamount of clearance both above and below the shiftless wafer blade. Incertain embodiments, the wafer may be moved in the slit opening and/orchamber from a lower position to an upper position via pins to extendabove the shiftless wafer blade and then be lowered onto the shiftlesswafer blade within the deep wafer pocket of the shiftless wafer blade.The movement of the wafer within the slit opening onto the shiftlesswafer blade may be performed in a conventional manner and will not bediscussed in further detail herein.

At operation 604, the shiftless wafer blade may transfer the wafer. Asnoted above, the shiftless wafer blade may be connected with, and movedby, a robotic handler. The robotic handler may handle the wafer transferby a single, planar, two-axis, random access, cassette-to-cassettemotion or a cassette-to-chamber motion.

At operation 606, the wafer may be deposited using the shiftless waferblade. Similar to being received, the wafer may be deposited, forexample, within a slit opening of a cassette and/or a chamber. Incertain embodiments, the shiftless wafer blade may be extended into theslit opening of the cassette and/or extended into the chamber. The wafermay be moved in the slit opening and/or chamber from a lower position toan upper position via pins to extend above and off the shiftless waferblade and then be lowered within the cassette and/or chamber. Themovement of the wafer within the slit opening onto the shiftless waferblade may be performed in a conventional manner and will not bediscussed in further detail herein.

In an embodiment, a system includes: a cassette comprising a slitopening configured to house a wafer; a blade configured to move thewafer to and from the slit opening by extending into the slit opening,wherein a blade thickness of the blade is at most ⅖ of a height of theslit opening and wherein the blade is configured to secure the waferwithin a pocket on the blade that is at least ⅔ of a wafer thickness ofthe wafer.

In another embodiment, a system includes: a cassette comprising a slitopening configured to house a wafer; a blade configured to move thewafer to and from the slit opening by extending into the slit opening byan extension depth as measured from an extreme end of the blade, whereinthe blade is configured to secure the wafer within a contour on theblade; wherein each corner of the blade within the extension depth isrounded.

In another embodiment, a method includes: extending a blade into a slitopening of a cassette, wherein a blade thickness of the blade is at most⅖ of a height of the slit opening; securing a wafer on the blade withinthe slit opening, wherein the blade is configured to secure the waferwithin a pocket on the blade that is at least ⅔ of a wafer thickness ofthe wafer; transporting the wafer on the blade from the slit opening toa processing chamber; and depositing the wafer in the processingchamber.

The foregoing outlines features of several embodiments so that those ofordinary skill in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodimentsintroduced herein. Those skilled in the art should also realize thatsuch equivalent constructions do not depart from the spirit and scope ofthe present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

In this document, the term “module” as used herein, refers to software,firmware, hardware, and any combination of these elements for performingthe associated functions described herein. Additionally, for purpose ofdiscussion, the various modules are described as discrete modules;however, as would be apparent to one of ordinary skill in the art, twoor more modules may be combined to form a single module that performsthe associated functions according embodiments of the invention.

A person of ordinary skill in the art would further appreciate that anyof the various illustrative logical blocks, modules, processors, means,circuits, methods and functions described in connection with the aspectsdisclosed herein can be implemented by electronic hardware (e.g., adigital implementation, an analog implementation, or a combination ofthe two), firmware, various forms of program or design codeincorporating instructions (which can be referred to herein, forconvenience, as “software” or a “software module), or any combination ofthese techniques. To clearly illustrate this interchangeability ofhardware, firmware and software, various illustrative components,blocks, modules, circuits, and steps have been described above generallyin terms of their functionality. Whether such functionality isimplemented as hardware, firmware or software, or a combination of thesetechniques, depends upon the particular application and designconstraints imposed on the overall system. Skilled artisans canimplement the described functionality in various ways for eachparticular application, but such implementation decisions do not cause adeparture from the scope of the present disclosure.

Furthermore, a person of ordinary skill in the art would understand thatvarious illustrative logical blocks, modules, devices, components andcircuits described herein can be implemented within or performed by anintegrated circuit (IC) that can include a general purpose processor, adigital signal processor (DSP), an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA) or otherprogrammable logic device, or any combination thereof. The logicalblocks, modules, and circuits can further include antennas and/ortransceivers to communicate with various components within the networkor within the device. A general purpose processor can be amicroprocessor, but in the alternative, the processor can be anyconventional processor, controller, or state machine. A processor canalso be implemented as a combination of computing devices, e.g., acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other suitable configuration to perform the functionsdescribed herein.

Conditional language such as, among others, “can,” “could,” “might” or“may,” unless specifically stated otherwise, are otherwise understoodwithin the context as used in general to convey that certain embodimentsinclude, while other embodiments do not include, certain features,elements and/or steps. Thus, such conditional language is not generallyintended to imply that features, elements and/or steps are in any wayrequired for one or more embodiments or that one or more embodimentsnecessarily include logic for deciding, with or without user input orprompting, whether these features, elements and/or steps are included orare to be performed in any particular embodiment.

Additionally, persons of skill in the art would be enabled to configurefunctional entities to perform the operations described herein afterreading the present disclosure. The term “configured” as used hereinwith respect to a specified operation or function refers to a system,device, component, circuit, structure, machine, etc. that is physicallyor virtually constructed, programmed and/or arranged to perform thespecified operation or function.

Disjunctive language such as the phrase “at least one of X, Y, or Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to present that an item, term, etc., may beeither X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z).Thus, such disjunctive language is not generally intended to, and shouldnot, imply that certain embodiments require at least one of X, at leastone of Y, or at least one of Z to each be present.

It should be emphasized that many variations and modifications may bemade to the above-described embodiments, the elements of which are to beunderstood as being among other acceptable examples. All suchmodifications and variations are intended to be included herein withinthe scope of this disclosure and protected by the following claims.

What is claimed is:
 1. A system, comprising: a cassette comprising aslit opening configured to house a wafer; and a blade configured to movethe wafer to and from the slit opening by extending into the slitopening, wherein the blade is configured to secure the wafer within acontoured pocket on the blade, and wherein the blade further comprises:a first forward protrusion with rounded corners; a second forwardprotrusion with rounded corners, the second forward protrusion extendingparallel to the first forward protrusion; a first opening having aportion that extends into a part of the first forward protrusion; and asecond opening having a portion that extends into a part of the secondforward protrusion, wherein the first and second forward protrusionsrespectively.
 2. The system of claim 1, wherein: the blade is configuredto move the wafer to and from the slit opening by extending into theslit opening by an extension depth as measured from an extreme end ofthe blade, and each corner of the blade within the extension depth isrounded.
 3. The system of claim 1, wherein: the blade comprises a firstpart and a second part, wherein the second part is covered by a robotichandler and each corner of the blade within the first part is rounded.4. The system of claim 1, wherein the pocket is between a firstthickness of the blade and a second thickness of the blade that isthinner than the first thickness.
 5. The system of claim 1, wherein theblade comprises one of: quartz, steel, a ceramic, aluminum oxide, and analuminum alloy.
 6. The system of claim 1, wherein the cassette comprisesmultiple uniform slit openings and the slit opening is one of themultiple uniform slit openings.
 7. The system of claim 1, wherein theblade further comprises an upper pocket contour and a lower pocketcontour, wherein each of the upper and lower pocket contours compriserounded vertical outside corners and rounded horizontal outside corners.8. A system, comprising: a cassette comprising a slit opening configuredto house a wafer; and a blade configured to move the wafer to and fromthe slit opening by extending into the slit opening by an extensiondepth as measured from an extreme end of the blade, wherein the blade isconfigured to secure the wafer within a contour on the blade, andwherein the blade comprises a pocket contour defining an area in whichthe wafer rests, wherein the pocket contour comprises rounded verticaloutside corners and rounded horizontal outside corners.
 9. The system ofclaim 8, wherein a thickness of the blade is at most ⅖ of a height ofthe slit opening.
 10. The system of claim 8, wherein the blade comprisesa first thickness and a second thickness, which is thinner than thefirst thickness, wherein a height difference between the first thicknessand the second thickness is at least ⅔ of a thickness of the wafer. 11.The system of claim 10, wherein the blade comprises a third thickness,which is thinner than the second thickness.
 12. The system of claim 11,wherein the third thickness is laterally surrounded by the secondthickness.
 13. The system of claim 8, wherein the blade forms a simplyconnected topological space.
 14. The system of claim 8, wherein thewafer is flush with a surface of the blade while resting within thecontour of the blade.
 15. The system of claim 8, wherein the waferprotrudes from the blade while resting within the contour of the blade.16. A method, comprising: extending a blade into a slit opening of acassette; securing a wafer on the blade within the slit opening, whereinthe blade is configured to secure the wafer within a pocket on theblade, wherein the blade comprises at least one pocket contour formingat least a partial outline of a circle defining an area in which thewafer rests, wherein the at least one pocket contour comprises roundedvertical outside corners and rounded horizontal outside corners, andwherein the blade further comprises at least one forward protrusion withrounded corners and at least one opening having a portion that extendsinto a part of the at least one forward protrusion, respectively;transporting the wafer on the blade from the slit opening to aprocessing chamber; and depositing the wafer in the processing chamber.17. The method of claim 16, wherein: the blade is configured to extendinto the slit opening by an extension depth as measured from an extremeend of the blade, and each corner of the blade within the extensiondepth is rounded.
 18. The method of claim 16, wherein: the bladecomprises a first part and a second part, wherein the second part iscovered by a robotic handler and each corner of the blade within thefirst part is rounded.
 19. The method of claim 16, wherein the pocket isbetween a first thickness of the blade and a second thickness of theblade that is thinner than the first thickness.
 20. The method of claim16, wherein the blade comprises one of: quartz, steel, a ceramic,aluminum oxide, and an aluminum alloy.